VerifySettlement.kt

class VerifySettlement(private val otherSession: FlowSession) : FlowLogic<Unit>() {

  // .. omitting ..
  
  @Suspendable
    override fun call() {
      // .. omitting ..
      
      // 4. Handle different settlement methods.
        val verifyResult = when (settlementMethod) {
            is XrpSettlement -> verifyXrpSettlement(obligation, lastPayment as XrpPayment<TokenType>)
            is SwiftSettlement -> verifySwiftSettlement(lastPayment as SwiftPayment)
            /* INCLUDE OUR SETTLEMENT RAIL HERE! */
            is CustomSettlementMethod -> verifyCustomPaymentRailSettlement(..)
            else -> throw IllegalStateException("Invalid settlement method $settlementMethod.")
        }

      // .. omitting ..
    }
}